Polymerizable dental composition

ABSTRACT

A polymerizable composition for dental use, containing monomer (a) with a polymerizable olefinic unsaturated group, acylphosphine oxide (b), organic peroxide (c), tertiary amine (d) and aromatic sulfinic acid and/or a salt thereof (e). The polymerizable composition for dental use exerts excellent curability by any of photo-polymerization and chemical polymerization, having a good color for dental use, with less color change between prior to and after polymerization, and excellent light resistance, producing a cured product with a smaller thickness of the unpolymerized layer on the surface, having larger curing depth and excellent adhesion to teeth and metals and the like and great color fastness in hot water and in darkness. By taking advantages of these excellent properties, the polymerizable composition can effectively be used for utilities, for example as a bonding agent, a composite resin, an adhesive agent, a primer and an opaque primer and the like, for dental use.

This Application is a 371 of PCT/JP98/02488 dated Jun. 4, 1998.

TECHNICAL FIELD

The present invention relates to a novel polymerizable composition fordental use, being polymerizable by any method of photo-polymerizationand chemical polymerization, having less color change between prior toand after polymerization, generating cured products with great colorstability and having good surface curability and a short polymerizationtime.

Taking advantages of the great characteristic properties of thepolymerizable composition for dental use in accordance with the presentinvention, the composition can effectively be used as an adhesive, abonding agent, a composite resin, a surface treating agent, an opaqueprimer and the like, for dental use.

TECHNICAL BACKGROUND

In recent years, polymerizable resin materials have been used aspolymerizable compositions for dental use, widely in the entire fieldsof dental treatment, owing to the great processability such that thematerials can appropriately be molded into desired shapes, the goodaesthetic beauty such that the materials can restore damaged tooth as ifthe resulting tooth were natural, and the high strength of the curedproduct.

Since U.S. Pat. No. 3,066,112 issued in 1959 proposes the application ofpolyfunctional acrylic polymerizable resins to the treatment of caries,a great number of materials chemically polymerizable at ambienttemperature have been put to practical use. Thereafter, a dentalmaterial of ultraviolet polymerization has been proposed by usingbenzoin methyl ether and similar catalysts, in parallel to the progressof materials of chemical polymerization (Japanese Patent ApplicationLaid-Open No. 47-247).

Furthermore, a number of products have been developed, wherein a varietyof polymerization processes have been applied, including a dentalmaterial of photo-polymerization using camphorquinone (Japanese PatentApplication Laid-Open No. 48-49875).

Since then, photo-polymerizable materials containing camphorquinone havewidely been used as filling materials for dental use.

For applications where no effective level of light is incident evenafter photo-irradiation, for example for bonding of metal crowns, inlayand onlay, furthermore, dental materials of chemical polymerization arecurrently used.

Additionally, Japanese Patent Application Laid-Open No. 60-32810discloses a dental composition containing a catalyst system comprisingone of α-diketone compounds, namely camphorquinone, an organic peroxideand an amine, and describes that the thickness of the resultingunpolymerized layer on the surface is small.

Further, Japanese Patent Application Laid-Open No. 60-89407 describesthat a dental composition containing a catalyst system of the samecomposition as described above can attain very large curing depth.

These compositions for dental use, which contain a catalyst systemcomprising camphorquinone, organic peroxides and amines, have both thefunctions of chemical polymerization and photo-polymerization. Suchcomposition shave been used widely as adhesives and bonding agents fordental use, since the compositions have got good appraisal such that thecompositions can readily promote high polymerization degree on thesurfaces of materials owing to the function of photo-polymerization andcan also progress chemical polymerization even in depth where nosufficient light required for polymerization can reach.

However, camphorquinone itself has a color in vivid yellow,polymerizable compositions containing camphorquinone are colored yellowinappropriate for dental materials. Additionally, the vivid yellow ofthe polymerizable compositions containing camphorquinone fades throughphoto-irradiation, so that the color changes markedly between prior toand after polymerization. In recent years, the demand for aestheticbeauty from dental patients has been emphasized in the field of dentaltreatment, and it is said that the vivid yellow color and the colorchange between prior to and after polymerization are not suitable.

A combination of benzoyl peroxide, i.e. a polymerization initiator, andreducing agents such as tertiary amine, which has been used widely forchemically polymerizable compositions, is problematic in view of colorstability in that the color of the cured products of such compositionsreadily changes when the products are exposed to hot water.

For the purpose of overcoming the problems, a dental compositioncontaining acylphosphine oxide as a photo-polymerization initiator hasbeen proposed (Japanese Patent Publication No. 6-55654). The curedproducts resulted from the photo-polymerizable compositions containingacylphosphine oxide as a photo-polymerization initiator are excellent inits color stability, but the photo-polymerizable compositions aredisadvantageous in that polymerization is not sufficiently facilitatedin depth because the curing depth of the composition is shallower thanthat of the polymerizable compositions containing camphorquinone.

A technique for improving the affinity between teeth and such curedproducts thereby increasing the adhesion strength between teeth and thecured products, by using an acidic monomer having an acid group togetherwith a polymerizable unsaturated group for a part of polymerizablemonomers to be used in dental materials, has been on the way ofpractical use. Though polymerizable compositions containing acidicmonomers have such an advantage as stated above, the thickness of theresulting unpolymerized layer is so large that the hardness of theresulting cured product may be insufficient.

Because the burden over patients is less as the therapeutic treatmenttime is shorter, a dental material with such a high polymerization ratethat can be cured for a short period has been expected.

Therefore, it is an object of the present invention to provide apolymerizable composition for dental use, the composition being coloredsuitable as a dental material, having less color change between prior toand after polymerization (prior to and after curing) and such a largercuring depth to produce cured products with sufficient hardness andstrength even in depth.

Furthermore, it is the other object of the present invention to providea polymerizable composition for dental use, in addition to theproperties described above, being capable of producing cured productswith such a small thickness of the unpolymerized layer on the surfaceand a higher hardness, having a larger polymerization rate so thecomposition can be cured for a short period of time, and having greatadhesion to the teeth.

DISCLOSURE OF THE INVENTION

To attain the objects, the present inventors have made intensiveinvestigations. Consequently, the inventors have found that the use ofacylphosphine oxide as a photo-polymerization initiator, an organicperoxide as a chemical polymerization initiator, reducing agents such asthe combination of tertiary amine and aromatic sulfinic acid and/or asalt thereof for a polymerizable composition containing a monomer with apolymerizable olefinic unsaturated group can impart excellent curabilityto the resulting polymerizable composition through any ofphoto-polymerization and chemical polymerization, which can further havesuitable color for dental use, less color change between prior to andafter polymerization (prior to and after curing) and great lightresistance with less fading.

The present inventors have further found that cured products made fromthe polymerizable composition have a small thickness of theunpolymerized layer on the surface, a higher hardness; that thepolymerizable composition has such large curing depth to produce curedproducts with sufficient hardness and strength even in depth; and thatthe composition has so excellent resistance to discoloration by hotwater in darkness that the resulting cured products are hardlydiscolored even if the products are exposed to hot water in the oralcavity.

Still additionally, the present inventors have found that thepolymerizable composition containing a monomer with an acid grouptogether with a polymerizable olefinic unsaturated group, as a part ofthe polymerizable monomers in the composition, can more improve theadhesive strength to teeth while the resulting cured products can stillretain the various excellent properties described above. The inventorshave achieved the present invention on the basis of those findings.

It is not yet elucidated why the polymerizable composition according tothe present invention can have such various excellent properties asdescribed above, but it is speculated that an extremely great number ofradicals are generated on the irradiated surface because of the higherquantum yield of acylphosphine oxide to be used as component (b) in thepolymerizable composition, so that the polymerization heat and theradicals at such higher concentration on the surface may induce thedecomposition of organic peroxides.

Thus, the present invention is a polymerizable composition for dentaluse, the composition comprising monomer (a) with a polymerizableolefinic unsaturated group, acylphosphine oxide (b), organic peroxide(c), tertiary amine (d) and aromatic sulfinic acid and/or a saltthereof(e).

In accordance with the present invention, additionally, thepolymerizable composition for dental use, further containing a monomerwith a polymerizable olefinic unsaturated group and an acid group for apart of the monomer (a), is encompassed within the preferableembodiments.

EMBODIMENT OF THE INVENTION

The monomer (a) to be used in the present invention may be any ofmonomers with a polymerizable olefinic unsaturated group. Among them,(meth)acrylate monomers are preferably used as the monomer (a), from therespect of the simplicity of the polymerization procedure and the safetyfor biological organisms.

The (meth)acrylate monomer to be used preferably in the presentinvention may be any of mono-functional (meth)acrylate monomers andpolyfunctional (meth)acrylate monomers.

As such mono-functional (meth)acrylate monomers, use may preferably bemade of esters of (meth)acrylic acid having alkyl groups with 1 to 12carbon atoms and esters of (meth)acrylic acid containing aromatic groupswith 6 to 12 carbon atoms, wherein the alkyl groups and aromatic groupscomposing the esters may contain substituents such as hydroxyl group andether bonds.

Specific examples of the monofunctional (meth)acrylate monomers mayinclude (meth)acrylates such as methyl (meth)acrylate, ethyl(meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate,2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl(meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate,benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl(meth)acrylate, allyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate,methoxydiethylene glycol (meth)acrylate, methoxytetraethylene glycol(meth)acrylate, methoxypolyethylene glycol (meth)acrylate,phenoxy-diethyleneglycol (meth)acrylate, phenoxyhexaethyleneglycol(meth)acrylate, glycerol (meth)acrylate, tetrahydrofurfuryl(meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl(meth)acrylate, phenyl (meth)acrylate, pentaerythritolmono(meth)acrylate, dipentaerythritol mono(meth)acrylate, caprolactonemodified tetrahydrofurfuryl (meth)acrylate, caprolactone modifieddipentaerythritol (meth)acrylate, and caprolactone modified2-hydroxyethyl (meth)acrylate.

Furthermore, preferable examples of the polyfunctional (meth)acrylatemonomers may include di(meth)acrylates of alkylene glycol having 2 to 20carbon atoms, di(meth)acrylates of the oligomers of said alkyleneglycol, polyalkyleneglycol di(meth)acrylate, di(meth)acrylate derivedfrom bisphenol A, (meth) acrylate monomers having three or morefunctional groups; and the examples additionally may include urethane(meth)acrylate esters as reaction products of 2 moles of (meth)acrylatehaving a hydroxyl group and one mole of diisocyanate (refer to forexample polyfunctional urethane monomers disclosed in Japanese PatentPublication No. 55-33687 and Japanese Patent Application Laid-Open No.56-152408).

More specifically, the polyfunctional (meth)acrylate may include forexample ethylene glycol di(meth)acrylate, diethylene glycoldi(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethyleneglycol di(meth)acrylate, polyethylene glycol di(meth)acrylate,1,3-butylene glycol di(meth)acrylate, 1,6-hexane diol di(meth)acrylate,neopentyl glycol di(meth) acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, glyceroldi(meth)acrylate, bisphenol A A di(meth)acrylate, bisphenol A glycidyldi(meth)acrylate, ethylene oxide modified bisphenol A di(meth)acrylate,ethylene oxide modified bisphenol A glycidyl di(meth)acrylate,2,2-bis(4-methacryloxypropoxyphenyl) propane,7,7,9-trimethyl-4,13-dioxa-3,14-dioxo-5,12-diazahexadecane-1,16-dioldi(meth)acrylate, neopentyl glycol hydroxypivalic acid esterdi(meth)acrylate, caprolactone modified hydroxypivalic acid neopentylglycol ester di(meth)acrylate, trimethylol ethane di(meth)acrylate,trimethylol propane di(meth)acrylate, trimethylol methanetri(meth)acrylate, trimethylol ethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate,dipentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate,dipentaerythritol hexa(meth)acrylate, the reaction product of3-chloro-2-hydroxypropyl (meth)acrylate and methylcyclohexanediisocyanate, the reaction product of 2-hydroxypropyl (meth)acrylate andmethylcyclohexane diisocyanate, the reaction product of 2-hydroxypropyl(meth)acrylate and methylene bis (4-cyclohexylisocyanate), the reactionproduct of 2-hydroxypropyl(meth)acrylate and trimethylhexamethylenediisocyanate, the reaction product of 2-hydroxyethyl (meth)acrylate andisophorone diisocyanate, and the reaction product of3-chloro-2-hydroxypropyl (meth)acrylate and isophorone diisocyanate.

The present polymerizable composition for dental use may contain one ormore of the (meth)acrylate monomers described above. From the respect ofthe handling of the composition, curability and physical properties ofthe resulting cured products, the polymerizable composition for dentaluse preferably contains at least one of the monofunctional(meth)acrylate monomers and at least one of the polyfunctional(meth)acrylate monomers.

For using the present polymerizable composition for dental use as anadhesive and a bonding agent for dental use, furthermore, thecomposition preferably contains a strongly polar monomer having abilityto promote the adhesion between teeth and metals, particularly a monomerwith an acid group together with a polymerizable olefinic unsaturatedgroup (referred to as “acid monomer” hereinbelow) for a part of themonomer (a).

When the present polymerizable composition for dental use contains theacid monomer, the content of the acid monomer is preferably 1 to 70% byweight, more preferably 5 to 50% by weight on the basis of the totalweight of the monomer (a). The content of the acid monomer exceeding 70%by weight often causes deterioration of curing of the composition.

Examples of the acid group in the acid monomer may include the followinggroups of from phosphoric acid, diphosphate or derivatives thereof;

(wherein Z represents a halogen atom), carboxyl group (—COOH),carbohalide group (—COZ) (wherein Z represents a halogen atom),carboxylic anhydride group.

Specific examples of the acid monomer with the acid group may includewhat will be shown below.

In accordance with the present invention, one or two or more of the acidmonomers described above, for a part of the monomer (a), can be used incombination with one or two or more of the (meth)acrylates with no acidgroup.

The acylphosphine oxide (b) to be used in accordance with the presentinvention has a primary action as photo-polymerization initiator, toinitiate the polymerization of the monomer (a) in the polymerizablecomposition on photo-irradiation.

As the acylphosphine oxide (b) to be used in accordance with the presentinvention, use may be made of any acylphosphine oxide capable ofinitiating the polymerization of the monomer (a) on photo-irradiation,and specifically, use is preferably made of the acylphosphine oxidecompound represented by the following general formula (I).

(wherein R¹ represents an alkyl group or an aryl group; R² represents analkyl group, an aryl group or a group represented by the formula —OR³wherein R³ represents an alkyl group or an aryl group; and Ac representsan acyl group.)

As the acylphosphine oxide (b) among them in accordance with the presentinvention, use is preferably made of benzoyldiphenylphosphine oxidewithin the general formula (I) wherein R¹ and R² are phenyl groups whichmay have or may not have substituent(s); and benzoylphenyl phosphinateester wherein R¹ represents a phenyl group which may have or may nothave substituent(s), R² represents a group represented by the formula—OR³, and Ac represents a benzoyl group which may have or may not havesubstituent(s).

Specific examples of the benzoyldiphenylphosphine oxide andbenzoylphenyl phosphinate ester to be preferably used in accordance withthe present invention may include2,4,6-trimethylbenzoyldiphenylphosphine oxide,2,6-dimethylbenzoyldiphenylphosphine oxide,2,6-dimethoxylbenzoyldiphenylphosphine oxide,2,6-dichlorobenzoyldiphenylphosphine oxide,2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide,2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester,2,4,6-trimethylbenzoylphenylphosphinic acid ethyl ester, and 2,4,6-trimethylbenzoylphenylphosphinic acid phenyl ester, and one or two ormore of these compounds may be used.

As the acylphosphine oxide (b) among them in accordance with the presentinvention, use is particularly preferably made of2,4,6-trimethylbenzoyldiphenylphosphine oxide represented by thefollowing chemical formula (II) and/or2,4,6-trimethylbenzoylphenylphosphinic acid alkyl ester represented bythe chemical formula (III), from the respect of its stability.

(wherein R⁴ represents an alkyl group with one to 4 carbon atoms.)

The content of the acylphosphine oxide (b) in the polymerizablecomposition is preferably 0.05 to 20% by weight, more preferably 0.1 to10% by weight on the basis of the weight of the monomer (a), in view ofthe adjustment of the photo-sensitivity of the polymerizablecomposition.

The organic peroxide (c) to be used in accordance with the presentinvention may be any organic peroxide capable of initiating thepolymerization of the monomer (a) through thermal or redox reaction,specifically including diacyl peroxides, peroxyesters, dialkylperoxides, peroxyketals, ketone peroxides, and hydroperoxides. Specificexamples of the diacyl peroxides may include benzoyl peroxide,2,4-dichlorobenzoyl peroxide, and m-toluoyl peroxide. Specific examplesof the peroxyesters may include t-butylperoxybenzoate,bis-t-butylperoxyisophthalate,2,5-dimethyl-2,5-bis(benzoylperoxy)hexane,t-butylperoxy-2-ethylhexanoate, and t-butylperoxyisopropylcarbonate.Specific examples of the dialkyl peroxides may include dicumyl peroxide,di-t-butyl peroxide, and lauroyl peroxide. Additionally, specificexamples of the peroxyketals may include1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane. And specific examplesof the ketone peroxides may include methyl ethyl ketone peroxide. Then,specific examples of the hydroperoxides may include t-butylhydroperoxide. One or two or more of these organic peroxides may be usedsatisfactorily.

So as to impart a proper polymerization rate to the polymerizablecomposition for dental use, the content of the organic peroxide (C) inthe polymerizable composition in accordance with the present inventionis preferably 0.05 to 20% by weight, more preferably 0.1 to 10% byweight on the basis of the weight of the monomer (a).

The tertiary amine (d) to be used in accordance with the presentinvention primarily functions as a reducing agent. As the tertiary amine(d), any tertiary amine is satisfactory as long as it functions as areducing agent in combination with an aromatic sulfinic acid or a saltthereof in the presence of the acylphosphine oxide (b) and the organicperoxide (c). They include aromatic tertiary amine and/or aliphatictertiary amine. Specific examples of the aromatic tertiary amine mayinclude N,N-dimethylaniline, N,N-dimethyl-p-toluidine,N,N-dimethyl-m-toluidine, N,N-diethyl-p-toluidine,N,N-dimethyl-3,5-dimethylaniline, N,N-dimethyl-3,4-dimethylaniline,N,N-dimethyl-4-ethylaniline, N,N-dimethyl-4-i-propylaniline,N,N-dimethyl-4-t-butylaniline, N,N-dimethyl-3,5-di t-butylaniline,N,N-bis(2-hydroxyethyl)-p-toluidine,N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline,N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline,N,N-bis(2-hydroxyethyl)-4-ethylaniline,N,N-bis(2-hydroxyethyl)-4-i-propylaniline,N,N-bis(2-hydroxyethyl)-4-t-butylaniline, N,N-bis(2-hydroxyethyl)-3,5-dii-propylaniline, N,N-bis(2-hydroxyethyl)-3,5-di t-butylaniline,4-dimethylaminobenzoate ethyl, 4-dimethylaminobenzoate n-butoxyethyl,and 4-dimethylaminobenzoate (2-methacryloyloxy)ethyl. Furthermore,specific examples of the aliphatic tertiary amine (d) may includetrimethylamine, triethylamine, N-methyldiethanolamine,N-ethyldiethanolamine, N-n-butyldiethanolamine, N-lauryldiethanolamine,triethanolamine, (2-dimethylamino)ethyl methacrylate,N-methyldiethanolamine dimethacrylate, N-ethyldiethanolaminedimethacrylate, triethanolamine monomethacrylate, triethanolaminedimethacrylate, and triethanolamine trimethacrylate.

In accordance with the present invention, one or two or more of thesetertiary amines may be used.

From the respect of imparting a proper polymerization rate andsuppressing discoloration, the content of the tertiary amine (d) in thepolymerizable composition for dental use in accordance with the presentinvention is preferably 0.05 to 10% by weight, more preferably 0.1 to 5%by weight on the basis of the weight of the monomer (a).

The aromatic sulfinic acid or a salt thereof (e) (referred to as“aromatic sulfinic acid (salt) (e)”) to be used in accordance with thepresent invention primarily functions as a reducing agent. As thearomatic sulfinic acid (salt) (e), any aromatic sulfinic acid (salt) (e)is satisfactory as long as it functions as a reducing agent incombination with the tertiary amine (d) in the presence of theacylphosphine oxide (b) and the organic peroxide (c). Specific examplesthereof include benzenesulfinic acid, sodium benzenesulfinate,potassiumbenzenesulfinate, calciumbenzenesulfinate, lithiumbenzenesulfinate, toluenesulfinic acid, sodium toluenesulfinate,potassium toluenesulfinate, calcium toluenesulfinate, lithiumtoluenesulfinate, 2,4,6-trimethylbenzenesulfinic acid,2,4,6-trimethylsodium benzenesulfinate, 2,4,6-trimethylbenzenesulfinatepotassium, 2,4,6-trimethylbenzenesulfinate calcium,2,4,6-trimethylbenzenesulfinate lithium, 2,4,6-triethylbenzenesulfinicacid, 2,4, 6-triethylsodium benzenesulfinate2,4,6-triethylbenzenesulfinate potassium, 2,4,6-triethylbenzenesulfinatecalcium, 2,4,6-i-propylbenzenesulfinic acid, 2,4,6-i-propylsodiumbenzenesulfinate , 2,4,6-i-propylbenzenesulfinate potassium, and2,4,6-I-propylbenzenesulfinate calcium. For the polymerizablecomposition for dental use in accordance with the present invention, oneor two or more of these aromatic sulfinic acids (salts) may be used.

From the respect of imparting a proper polymerization rate, the contentof the aromatic sulfinic acid (salt) (e) in the polymerizablecomposition for dental use in accordance with the present invention ispreferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight onthe basis of the weight of the monomer (a).

In combination with the monomer (a), the polymerizable composition fordental use in accordance with the present invention essentially containsthe acylphosphine oxide (b), the organic peroxide (c), the tertiaryamine (d) and the aromatic sulfinic acid (salt) (e).

When the polymerization composition for dental use containingcamphorquinone instead of acylphosphine oxide (b), the thickness of theunpolymerized layer on the surface of the resulting cured product fromthe composition is large, whereby the hardness thereof is decreased, aswell as causing the reduction of the light resistance of the curedproduct, thereby leading to the increase of the color change betweenprior to and after polymerization. When the polymerizable compositionfor dental use does not contain the tertiary amine (d), alternatively,the curing depth of the composition is less. When the polymerizablecomposition for dental use does not contain the aromatic sulfinic acid(salt) (e), furthermore, the thickness of unpolymerized layer on thesurface of theresulting cured product is large, whereby the hardnessthereof is decreased, as well as causing the reduction of the lightresistance of the cured product, thereby leading to the enhancement ofthe color change between prior to and after polymerization.

From the respect of the stability of the composition, during storage andbefore use of the composition, the polymerizable composition for dentaluse in accordance with the present invention should be prepared inmulti-package , wherein the organic peroxide (c) is separated from thetertiary amine (d) and the aromatic sulfinic acid (salt) (e). Themulti-packing includes (i) two packages comprising the first packagecontaining the monomer (a), the acylphosphine oxide (b) and the organicperoxide (c) and the second package containing the tertiary amine (d)and the aromatic sulfinic acid (salt) (e); (ii) two packages comprisingthe first package containing a part of the monomer (a), theacylphosphine oxide (b) and the organic peroxide (c) and the secondpackage containing the remaining part of the monomer (a), the tertiarymine (d) and the aromatic sulfinic acid (salt) (e); (iii) two packagescomprising the first package containing the monomer (a) and the organicperoxide (c) and the second package containing the acylphosphine oxide(b), the tertiary amine (d) and the aromatic sulfinic acid (salt) (e);(iv) three packages comprising the first package containing a part ofthe monomer (a), the acylphosphine oxide (b) and the organic peroxide(c), the second package containing the remaining part of the monomer (a)and the tertiary mine (d), and the third package containing theremaining part of the monomer (a) and the aromatic sulfinic acid(salt)(e).

The polymerizable composition for dental use in accordance with thepresent invention may satisfactorily contain a filler, if necessary, incombination with the components described above. Particularly when thepolymerizable composition for dental use in accordance with the presentinvention is used for a bonding agent or a composite resin for dentaluse, the composition preferably contains a filler, from the respect ofthe strength of the resulting cured product.

The content of a filler in the polymerizable composition for dental useis preferably at a ratio of the monomer (a): =the filler=100:0 to 10:90(in weight ratio). Particularly when the polymerizable composition fordental use in accordance with the present invention is a bonding agentor a composite Iresin, the composition preferably contains a fillerwithin a ratio of the monomer (a):the filler=80:20 to 10:90 (in weightratio); when the polymerizable composition is an adhesive agent, thecomposition preferably contains a filler within a ratio of the monomer(a):the filler=70:30 to 100:0 (in weight ratio).

The filler may satisfactorily be any of inorganic fillers, organicfillers, inorganic and organic complex fillers, or a mixture ofinorganic fillers and organic fillers.

Examples of such inorganic fillers may include soda glass, lithiumborosilicate glass, barium glass, strontium glass, zinc glass,fluoroaluminum borosilicate glass, borosilicate glass, crystal quartz,fumed silica, synthetic silica, alumina silicate, amorphous silica,glass ceramics or mixtures thereof.

From the respect of uniformity for mixing, generally, the particle sizeof the inorganic fillers is preferably 150 μm or less, more preferably100 μm or less, but inorganic fillers outside above limitation may alsobe used. If necessary, several types of inorganic fillers with differentparticle sizes may be mixed together and the resulting mixture maysatisfactorily be used.

So as to improve the affinity with the monomer (a) and with theresulting cured product after polymerization, preferably, the inorganicfillers may be subjected to surface treatment. As such surface treatingagent, use may satisfactorily be made of conventionally known silanecompounds (silane coupling m-,z agents), specifically including forexample vinyltrimethoxysilane, vinyltriethoxysilane,vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane,γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane,γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

The organic fillers may include organic polymer powder which ispreliminarily produced by polymerizing the monomer (a).

Additionally, use may satisfactorily be made of composite fillersrecovered by polymerizing a polymerizable monomer in the presence of aninorganic filler in dispersion.

The present polymerizable composition for dental use may containfluoride releasing fillers, for example polysiloxane coated metalfluorides as described in Japanese Patent Application Laid-Open No.10-36116, and in that case, a polymerizable composition for dental usewith an effect of preventing caries can be obtained.

The present photo-polymerizable composition for dental use may containpolymerization inhibitors, ultraviolet absorbents, pigments, andsolvents. Specific examples of the solvents may include water, ethanol,i-propanol, acetone, dimethylsulfoxide, dimethylformamide, ethylacetate, butyl acetate, and one or two or more of these solvents may beused.

The polymerizable composition of the present invention can effectivelybe used for utilities, for example as cements for dental use, such asresin cement and resin reinforced glass ionomer cement, composite resinsfor dental use and compomers for dental use, such as filling andrestorative materials, core build-up materials, pits and fissuresealant; adhesives for dental use, such as bonding agents and adhesivesfor orthodontic devices; dental primers; opaque primers and the like.

For using the present polymerizable composition for dental use as acomposite resin, even a deep cavity can be filled, owing to the largecuring depth, so that a cured product with greater hardness is yieldedeven in such depth, effectively retaining aesthetic beauty with lessdiscoloration.

When the present polymerizable composition for dental use is used as acement, the composition has such greater surface curability that thewear of cement lines can be prevented, with less discoloration, whicheffectively works to retain aesthetic beauty.

When the present polymerizable composition for dental use is used as abonding agent, the composition has such a larger polymerization ratethat the adhesion procedure is simple, which works to readily promotetreatment procedures by using other restorative materials such ascomposite resin.

When the present polymerizable composition for dental use is used asprimer, the composition has such excellent curability of penetratedcomponents into the tooth that the adhesion can be improved.

Additionally, the polymerizable composition of the present invention maysatisfactorily be used as coating agents, adhesives and fillingmaterials for general industries, besides dental uses.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in detail in the followingexamples, but it is in no way intended to be limited by these examples.

In the following examples, the properties of the polymerizablecomposition or the cured product thereof after polymerization weremeasured as follows.

(1) Thickness of Surface Unpolymerized Layer

In the following examples and comparative examples, the compositions Aand B were equally weighed and mixed together, to prepare individualpolymerizable compositions for dental use, which were then filled in amold made of Teflon having a diameter of 10 mm and a thickness of 1 mm,followed by smoothing of the surface and subsequent irradiation with adental irradiator (manufactured by Morita Corporation; “Lightel II”) for20 seconds. After irradiation, the unpolymerized part on the surface waswiped off, and then, the thickness of the unpolymerized layer wascalculated on the basis of the change in weight between prior to andafter the wiping procedure.

(2) Brinell Hardness

In the following examples and comparative examples, the compositions Aand B were equally weighed and mixed together, to prepare individualpolymerizable compositions for dental use, which were then filled in ametal mold of a diameter of 10 mm and a thickness of 5 mm, followed bycovering under pressure with a glass plate, and the compositions wereleft to stand in darkness at 37° C. for 30 minutes, to prepare productscured through chemical polymerization. The Brinell hardness of thesurface of each cured product was measured, after taking the glass plateoff, by using Microbrinell Hardness Tester (manufactured by Mori TesterSeisakusho).

(3) Curing Depth

In the following examples and comparative examples, the compositions Aand B were equally weighed and mixed together, to prepare individualpolymerizable compositions for dental use, which were then filled in ametal mold of a diameter of 4 mm and a height of 12 mm, followed bycovering with cover glass, and then, the compositions were irradiatedfrom the above with a dental irradiator (manufactured by MoritaCorporation; “Lightel II”) for 20 seconds. Immediately afterirradiation, the cured products were removed out of the mold, to wipeoff the unpolymerized layer and measured the height of the curedproducts with a slide gauge.

(4) Light Resistance (ΔE₁)

In the following examples and comparative examples, the compositions Aand B were equally weighed and mixed together, to prepare individualpolymerizable compositions for dental use, which were then filled in ametal mold of a diameter of 20 mm and a thickness of 1 mm, followed byphoto-irradiation with a dental irradiator (manufactured by Morita TokyoCorporation; “α-Light II”) for 5 minutes to cure the composition. A halfsurface of each of the cured product was covered with aluminium foil,followed by irradiation of light of 150,000 lux in water at 37° C. for24 hours. By using a color measuring system (manufactured by NipponDenshoku; “Σ90”), the colors of the resulting non-irradiated facecovered by aluminium foil and the resulting irradiated face were countedon an L*a*b* color specification system. Then, the color differencebetween above-mentioned two faces was determined by the followingequation; ΔE₁=(ΔL*²+Δa*²+Δb*²)^(½), which was used as an indicator oflight resistance.

(5) Color Change Between Prior to and After Polymerization (ΔE₂)

In the following examples and comparative examples, the compositions Aand B were equally weighed and mixed together, to prepare individualpolymerizable compositions for dental use, which were then filled in ametal mold of a diameter of 20 mm and a thickness of 1 mm, to count thecolors on an L*a*b* color specification system by using a colormeasuring system (manufactured by Nippon Denshoku; “Σ90”). Then, thecompositions were irradiated with a dental irradiator (manufactured byMorita Tokyo Corporation; “α-Light III”) for 5 minutes, and the colorsof the resulting cured products were counted in the same manner, todetermine the color change between prior to and after polymerization bythe following equation

ΔE₂=(ΔL*²+Δa*²+Δb*²)^(½).

(6) Color Fastness in Hot Water and in Darkness (ΔE₃)

In the following examples and comparative examples, the compositions Aand B were equally weighed and mixed together, to prepare individualpolymerizable compositions for dental use, which were then filled in ametal mold of a diameter of 20 mm and a thickness of 1 mm and were thenleft to stand in darkness at 37° C. for 30 minutes, to prepare curedproducts. By using a color difference meter (manufactured by NipponDenshoku; “Σ90”), the color of the resulting cured products was countedon an L*a*b* color specification system. Then, the cured products wereplaced in hot water (purified water) at 70° C. in darkness for one week.After drawing out the products from the water, the color was counted ina similar manner, to determine the color change between prior to andafter immersion in hot water, by the following equationΔE₃=(ΔL*²+Δa*²+Δb*²)^(½).

(7) Photo-polymerization Time

In the following examples and comparative examples, the compositions Aand B were equally weighed and mixed together, and the tip of athermocouple was immediately inserted into the resulting mixtures(polymerizable compositions), followed by photo-irradiation with adental irradiator (manufactured by Morita Corporation; “Lightel II”).The time required for the temperature of the polymerization heat toreach the peak, monitoring with the thermocouple, was designated asphoto-polymerization time.

EXAMPLES 1 to 3 AND COMPARATIVE EXAMPLES 1 AND 2

(i) By using bisphenol A A diglycidyl ether (abbreviated as “Bis-GMA”hereinafter), triethylene glycol dimethacrylate (abbreviated as “TEGDMA”hereinafter), 10-methacryloyloxy-decyldihydrogen phosphate (abbreviatedas “MDP” hereinafter) and 2-hydroxyethyl methacrylate (abbreviated as“HEMA” hereinafter) as the monomer (a), and by using2,4,6-trimethylbenzoyldiphenylphosphine oxide or2,4,6-trimethylbenzoylphenylphosphinate ethyl ester as the acylphosphineoxide (b), benzoyl peroxide as the organic peroxide (c) andN,N-bis(2-hydroxyethyl)-p-toluidine (abbreviated as“diethanol-p-toluidine” hereinafter) as the tertiary amine (d), andsodium benzenesulfinate as the aromatic sulfinic acid (salt) (e), incombination with camphorquinone, quartz powder and polysiloxane coatedsodium fluoride, all the above substances being at the amounts shown inTable 1 below, two polymerizable compositions for dental use, thecomposition A and the composition B, were prepared respectively.

(ii) By using the polymerizable compositions for dental use as preparedabove in (i), the thickness of the unpolymerized layer on the surface,Brinell hardness and light resistance of the cured products from thepolymerizable compositions were measured according to the methodsdescribed above. The results are as shown in Table 1 below.

TABLE 1 Compara- Compara- Ex- Ex- Ex- tive tive ample 1 ample 2 ample 3Example 1 Example 2 [Polymerizable compositions for dental use]Composition A (parts by weight): Monomer (a)¹⁾ Bis-GMA 40 40 40 40 40TEGDMA 40 40 40 40 40 MDP 20 20 20 20 20 Component (b)²⁾ b₁ 2 0 2 0 2 b₂0 2 0 0 0 Component (c) Benzoyl peroxide 2 2 2 2 2 Camphorquinone 0 0 02 0 Quartz powder 300 300 300 300 300 Composition B (parts by weight):Monomer (a)¹⁾ Bis-GMA 20 20 20 20 20 TEGDMA 30 30 30 30 30 HAMA 50 50 5050 50 Component (d) Diethanol-p- 1 1 1 1 1 toluidine Component (e)Sodium 1 1 1 1 0 benzenesulfinate Polysiloxane coated 0 0 30 0 0 sodiumfluoride Quartz powder 300 300 270 300 300 [Properties] Thickness of21.3 23.5 22.8 34.7 47.3 unpolymerized layer (μm) Brinell hardness 41.539.6 42.1 38.9 21.3 (HB) Light resistance 5.56 4.98 5.23 9.96 9.92 (ΔE₁) ¹⁾Monomer (a) Bis-GMA: bisphenol A diglycidyldimethacrylate TEGDMA:triethyleneglycol dimethacrylate MDP: 10-methacryloyloxydecyldihydrogenphosphate HEMA: 2-hydroxyethyl methacrylate ²⁾Component (b)[acylphosphine oxide] b₁: 2,4,6-trimethylbenzoyldiphenylphosphine oxideb₂: 2,4,6-trimethylbenzoylphenylphosphinate ethyl ester

The results in Table 1 above indicate that the polymerizablecompositions containing the monomer (a), the acylphosphine oxide (b),the organic peroxide (c), the tertiary amine (d) and the aromaticsulfinic acid (salt) (e) for dental use in Examples 1 to 3 haveexcellent surface curability because of the small thickness of theunpolymerized layers on the surface, high Brinell hardness and excellentchemical curability, and smaller values of ΔE₁ showing superior lightresistance.

The polymerizable composition with no acylphosphine oxide (b) containedtherein for dental use in Comparative Example 1 has a larger thicknessof the unpolymerized layer on the surface than those in Examples 1 to 3,indicating far poorer surface curability, and has larger values of ΔE₁than those in Examples 1 to 3, indicating poor light resistance.

The polymerizable composition with no tertiary amine (d) containedtherein for dental use in Comparative Example 2 has a far largerthickness of the unpolymerized layer on the surface than those inExamples 1 to 3, indicating poorer surface curability, and has far lowerBrinell hardness than those of Examples 1 to 3, showing poorer chemicalcurability, and larger values of ΔE₁ than those in Examples 1 to 3,showing poor light resistance.

EXAMPLES 4 to 6 AND COMPARATIVE EXAMPLES 3 to 4

(i) By using bisphenol A diglycidyl ether (Bis-GMA) andtriethyleneglycol dimethacrylate (TEGDMA) as the monomer (a) and byusing 2,4,6-trimethylbenzoyldiphenylphosphine oxide or2,4,6-trimethylbenzoylphenylphosphinate ethyl ester as the acylphosphineoxide (b), benzoyl peroxide as the organic peroxide (c) anddiethanol-p-toluidine or 4-dimethylaminobenzoate ethyl as the tertiaryamine (d), and sodium benzenesulfinate as the aromatic sulfinic acid(salt) (e), in combination with camphorquinone, quartz powder and bariumglass, all the above substances being at the ratios shown in Table 2below, two polymerizable compositions for dental use, comprising thecomposition A and the composition B, were individually prepared as shownin the following Table 2.

(ii) By using the polymerizable compositions for dental use as preparedabove in (i), the curing depth and the color difference (ΔE₂) betweenprior to and after polymerization were measured according to the methodsdescribed above. The results are as shown in Table 2 below.

TABLE 2 Compara- Compara- Ex- Ex- Ex- tive tive ample 4 ample 5 ample 6Example 3 Example 4 [Polymerizable compositions for dental use]Composition A (parts by weight): Monomer (a)¹⁾ Bis-GMA 70 70 70 70 70TEGDMA 30 30 30 30 30 Component (b)²⁾ b₁ 1 0 1 0 1 b₂ 0 1 0 0 0Component (c) Benzoyl peroxide 2 2 2 2 2 Camphorquinone 0 0 0 1 0 Bariumglass 400 400 400 400 400 Composition B (parts by weight): Monomer (a)¹⁾Bis-GMA 70 70 70 70 70 TEGDMA 30 30 30 30 30 Component (d) Diethanol-p-2 2 0 2 0 toluidine 4-dimethylamino- 0 0 2 0 0 benzoate ethyl Component(e) Sodium 2 2 2 2 2 benzenesulfinate Quartz powder 350 350 350 350 350[Properties] Curing depth (mm) 4.86 4.66 5.16 4.52 3.28 Color difference5.55 5.22 5.64 8.64 5.81 between prior to and after polymeri- zation (ΔE₂) ¹⁾Monomer (a) Bis-GMA: bisphenol A diglycidyl dimethacrylate TEGDMA:triethyleneglycol dimethacrylate ²⁾Component (b) [acylphosphine oxide]b₁: 2,4,6-trimethylbenzoyldiphenylphosphine oxide b₂:2,4,6-trimethylbenzoylphenylphosphinate ethyl ester

The results in Table 2 above indicate that the polymerizablecompositions containing the monomer (a), the acylphosphine oxide (b),the organic peroxide (c), the tertiary amine (d) and the aromaticsulfinic acid (salt) (e) for dental use in Examples 4 to 6 have largercuring depth with higher photo-polymerization, and smaller values ofcolor difference (ΔE₂) between prior to and after polymerization,.suggesting excellent color.

Alternatively, the polymerizable composition containing camphorquinonein place of the acylphosphine oxide (b) in Comparative Example 3 has asmaller curing depth than those in Examples 4 to 6, indicating poorerphoto-polymerization, and larger values of color difference (ΔE₂)between prior to and after polymerization, showing that the color of thecomposition largely changes between prior to and after polymerization.

The polymerizable composition with no tertiary amine (d) containedtherein for dental use in Comparative Example 4 has far smaller curingdepth than those in Examples 4 to 6, indicating far poorerphoto-polymerization than those of Examples 4 to 6, and larger values ofcolor difference (ΔE₂) between prior to and after polymerization,showing larger color change between prior to and after polymerization.

EXAMPLES 7 AND 8 AND COMPARATIVE EXAMPLE 5

(i) By using bisphenol A diglycidyl ether (Bis-GMA), triethyleneglycoldimethacrylate (TEGDMA), 10-methacryloyloxydecyldihydrogen phosphate(MDP) and 2-hydroxyethyl methacrylate (HEMA) as the monomer (a), and byusing 2,4,6-trimethylbenzoyldiphenylphosphine oxide or2,4,6-trimethylbenzoylphenylphosphinate ethyl ester as the acylphosphineoxide (b), benzoyl peroxide as the organic peroxide (c) anddiethanol-p-toluidine as the tertiary amine (d), and sodiumbenzenesulfinate as the aromatic sulfinic acid (salt) (e), incombination with camphorquinone and colloidal silica, all the abovesubstances being at the amounts shown in Table 3 below, twopolymerizable compositions for dental use, comprising the composition Aand the composition B as shown in Table 3 were individually prepared.

(ii) By using the polymerizable compositions for dental use as preparedabove in (i), the photo-polymerization time was measured according tothe method described above. The results are as shown in Table 3 below.

TABLE 3 Comparative Example 7 Example 8 Example 5 [Polymerizablecompositions for dental use] Composition A (parts by weight): Monomer(a)¹⁾ Bis-GMA 50 50 50 TEGDMA 40 40 40 MPD 10 10 10 Component (b)²⁾ b₁ 30 0 b₂ 0 3 0 Component (c) Benzoyl peroxide 2 2 2 Camphorquinone 0 0 3Colloidal silica 10 10 10 Composition B (parts by weight): Monomer (a)¹⁾Bis-GMA 30 30 30 TEGDMA 40 40 40 HEMA 30 30 30 Component (d)Diethanol-p-toluidine 2 2 2 Component (e) Sodium benzenesulfinate 2 2 2[properties] Photo-polymerization time 8 9 13 (seconds) ¹⁾Monomer (a)Bis-GMA: bisphenol A diglycidyl dimethacrylate TEGDMA: triethyleneglycoldimethacrylate MDP: 10-methacryloyloxydecyldihydrogen phosphate HEMA:2-hydroxyethyl methacrylate ²⁾Component (b) [acylphosphine oxide] b_(1:)2,4,6-trimethylbenzoyldiphenylphosphine oxide b₂:2,4,6-trimethylbenzoylphenylphosphinate ethyl ester

The results in Table 3 above indicate that the polymerizablecompositions containing the monomer (a), the acylphosphine oxide (b)i.e. 2,4,6-trimethylbenzoyldiphenylphosphine oxide or2,4,6-trimethylbenzoylphenylphosphinate ethyl ester, the organicperoxide (c) i.e. benzoyl peroxide, the tertiary amine (d) i.e.diethanol-p-toluidine and the aromatic sulfinic acid (salt) (e)i.e.sodium benzenesulfinate for dental use in Examples 7 and 8 have a shortphoto-polymerization time, suggesting that the compositions can bepolymerized and cured on photo-irradiation for a short time.

The polymerizable composition for dental use, containing camphorquinoneinstead of the acylphosphine oxide (b), in Comparative Example 5, has alonger photo-polymerization time than those in Examples 7 and 8,indicating that a longer time is required for polymerizing and curingthe composition on photo-irradiation.

EXAMPLES 9 AND 10 AND COMPARATIVE EXAMPLE 6

(i) By using bisphenol A A diglycidyl ether (Bis-GMA) andtriethyleneglycol dimethacrylate (TEGDMA) as the monomer (a),2,4,6-trimethylbenzoyldiphenylphosphine oxide or2,4,6-trimethylbenzoylphenylphosphinate ethyl ester as the acylphosphineoxide (b), benzoyl peroxide as the organic peroxide (c) anddiethanol-p-toluidine as the tertiary amine (d), and sodiumbenzenesulfinate as the aromatic sulfinic acid (salt) (e), incombination with camphorquinone and quartz powder, all the abovesubstances being at the ratios shown in Table 4 below, two polymerizablecompositions for dental use, comprising the composition A and thecomposition B as shown in Table 4 were individually prepared.

(ii) By using the polymerizable compositions for dental use as preparedabove in (i), the Brinell hardness and curing depth were measuredaccording to the methods described above. The results are as shown inTable 4 below.

TABLE 4 Example Comparative Example 9 10 Example 6 [Polymerizablecompositions for dental use] Composition A (parts by weight): Monomer(a)¹⁾ Bis-GMA 70 70 70 TEGDMA 30 30 30 Component (b)²⁾ b₁ 1 0 1 b₂ 0 1 0Component (d) Diethanol-p-toluidine 0.5 0.5 0 Component (e) Sodiumbenzenesulfinate 0.5 0.5 0.5 Quartz powder 400 400 400 Composition B(parts by weight): Monomer (a)¹⁾ Bis-GMA 70 70 70 TEGDMA 30 30 30Component (c) Benzoyl peroxide 2.5 2.5 2.5 Quartz powder 400 400 400[Properties] Brinell hardness (HB) 80.6 81.6 73.5 Curing depth (mm) 6.536.47 4.85 ¹⁾Monomer (a) Bis-GMA: bisphenol A diglycidyl dimethacrylateTEGDMA: triethyleneglycol dimethacrylate ²⁾Component (b) [acylphosphineoxide] b₁: 2,4,6-trimethylbenzoyldiphenylphosphine oxide b₂:2,4,6-trimethylbenzoylphenylphosphinate ethyl ester

The results above in Table 4 indicate that the polymerizablecompositions containing the monomer (a), the acylphosphine oxide (b),the organic peroxide (c), the tertiary amine (d) and the aromaticsulfinic acid (salt) (e) for dental use in Examples 9 and 10 havegreater Brinell hardness and excellent chemical polymerization as wellas larger curing depth, than those of the polymerizable composition fordental use in Comparative Example 6, suggesting excellentphoto-polymerization.

EXAMPLES 11 AND 12 AND COMPARATIVE EXAMPLE 7

(i) By using bisphenol A diglycidyl ether (Bis-GMA) andtriethyleneglycol dimethacrylate (TEGDMA) as the monomer (a), and byusing 2,4,6-trimethylbenzoyldiphenylphosphine oxide or2,4,6-trimethylbenzoylphenylphosphinate ethyl ester as the acylphosphineoxide (b), benzoyl peroxide as the organic peroxide (c) anddiethanol-p-toluidine as the tertiary amine (d), and sodiumbenzenesulfinate as the aromatic sulfinic acid (salt) (e), incombination with camphorquinone, all the above substances being at theratios shown in Table 5 below, two polymerizable compositions for dentaluse, comprising the composition A and the composition B as shown inTable 5 were individually prepared.

(ii) By using the polymerizable compositions for dental use as preparedabove in (i), the light resistance (ΔE₁), the color change (ΔE₂) betweenprior to and after polymerization and the color fastness in hot waterand in darkness (ΔE₃) were measured. The results are as shown in Table 5below.

TABLE 5 Example Example Comparative 11 12 Example 7 [Polymerizablecompositions for dental use] Composition A (parts by weight): Monomer(a)¹⁾ Bis-GMA 70 70 70 TEGDMA 30 30 30 Component (b)²⁾ b₁ 1 0 0 b₂ 0 1 0Component (d) Diethanol-p-toluidine 0.5 0.5 0.5 Component (e) Sodiumbenzenesulfinate 0.5 0.5 0.5 Camphorquinone 0 0 1 Composition B (partsby weight): Monomer (a)¹⁾ Bis-GMA 70 70 70 TEGDMA 30 30 30 Component (c)Benzoyl peroxide 1 1 1 [Properties] Light resistance (Δ E₁) 1.39 1.284.27 Color change between prior to and 1.26 1.28 3.65 afterpolymerization (Δ E₂) Color fastness in hot water and in 5.43 4.97 6.23darkness (Δ E₃) ¹⁾Monomer (a) Bis-GMA: bisphenol A diglycidyldimethacrylate TEGDMA: triethyleneglycol dimethacrylate ²⁾Component (b)[acylphosphine oxide] b₁: 2,4,6-trimethylbenzoyldiphenylphosphine oxideb₂: 2,4,6-trimethylbenzoylphenylphosphinate ethyl ester

The results in Table 5 above indicate that the polymerizablecompositions containing the monomer (a), the acylphosphine oxide (b),the organic peroxide (c), the tertiary amine (d) and the aromaticsulfinic acid (salt) (e) for dental use in Examples 11 and 12 have farsmaller light resistance values (ΔE₁) than the value of thepolymerizable composition with no acylphosphine oxide (b) containedtherein for dental use in Comparative Example 7, showing that thecompositions have excellent light resistance, and far smaller values(ΔE₂) of the color change between prior to and after polymerization,showing that the compositions have excellent color stability, andsmaller values of color fastness in hot water and in darkness (ΔE₃),showing that the color of the compositions is less discolored in hotwater and in darkness.

INDUSTRIAL APPLICABILITY

The polymerizable composition for dental use in accordance with thepresent invention exerts excellent curability by any ofphoto-polymerization and chemical polymerization.

Additionally, the polymerizable composition for dental use in accordancewith the present invention has a color suitable for dental use, withless color change between prior to and after polymerization (prior toand after curing), excellent light resistance and penetrated lessfading.

Furthermore, the polymerizable composition for dental use in accordancewith the present invention can produce a cured product with a smallerthickness of the unpolymerized layer on the surface and high hardness,and can additionally produce a cured product with sufficient hardnessand strength even in depth, because the composition has larger curingdepth.

The polymerizable composition for dental use in accordance with thepresent invention additionally has excellent color fastness in hot waterand in darkness, so that the composition is less discolored even if thecomposition is exposed to hot water in the oral cavity.

Still additionally, the polymerizable composition for dental use inaccordance with the present invention has excellent adhesion to teethand metals, and the composition has much more high adhesion to teeth incombination with an acid monomer with an acid group for a part of themonomer (a).

Accordingly, the polymerizable composition for dental use in accordancewith the present invention may effectively be used for utilities, forexample as bonding agents for dental use, such as resin cement and resinreinforced glass ionomer cement; composite resins for dental use andcompomers for dental use, such as fissure restorative materials, supportconstruction materials, sealant; adhesives for dental use, such as toothbonding agents and adhesives for orthodontic devices; dental primers;and opaque primers.

For using the present polymerizable composition for dental use as acomposite resin, in particular, even a deep cavity can be filled justonce because the curing depth of the composition is large, so that acured product with greater hardness is yielded even in such depth,effectively retaining aesthetic beauty with less discoloration.

When the present polymerizable composition for dental use is used as abonding agent, the composition additionally has such greater surfacecurability that the wear of cement lines can be prevented, with lessdiscoloration, which effectively works to retain aesthetic beauty.

When the present polymerizable composition for dental use is used as adental adhesive, furthermore, the composition has such a largerpolymerization rate that the application of the composition is simple,which works to readily promote treatment with other restorativematerials such as composite resin.

When the present polymerizable composition for dental use is used as adental primer, furthermore, the composition has such excellentcurability when penetrated into teeth that it shows much improvedadhesion to teeth.

What is claimed is:
 1. A polymerizable composition for dental use,comprising monomer (a) with at least one polymerizable olefinicunsaturated group, acylphosphine oxide (b), organic peroxide (c),tertiary amine (d) and aromatic sulfinic acid and/or a salt thereof (e).2. A polymerizable composition for dental use according to claim 1,comprising a monomer with at least one polymerizable olefinicunsaturated group and an acid group for a part of the monomer (a).
 3. Apolymerizable composition for dental use according to claim 1, whereinthe organic peroxide (c) is separately packed from the tertiary amine(d) and the aromatic sulfinic acid or a salt thereof (e).
 4. Apolymerizable composition for dental use according to claim 1,comprising the acylphosphine oxide (b) within a range of 0.05 to 20% byweight, the organic peroxide (c) within a range of 0.05 to 20% byweight, the tertiary amine (d) within a range of
 0. 5 to 10% by weightand the aromatic sulfinic acid and/or a salt thereof (e) within arangeof 0.05 to 10% by weight.
 5. A polymerizable composition for dental useaccording to claim 1, wherein the acylphosphine oxide (b) isbenzoyldiphenylphosphine oxide and/or benzoylphenylphosphinate esterwhich may have or may not have substituent respectively and the organicperoxide (c) is diacylperoxide.
 6. A polymerizable composition fordental use according to claim 1, wherein the acylphosphine oxide (b) is2,4,6-trimethylbenzoyldiphenylphosphine oxide and/or2,4,6-trimethylbenzoylphenylphosphinate alkyl ester and the organicperoxide (c) is benzoyl peroxide.
 7. A polymerizable composition fordental use according to claim 1, wherein the monomer (a) is a(meth)acrylate monomer.
 8. A polymerizable composition for dental useaccording to claim 1, comprising a filler a t a weight ratio of themonomer:the filler=99.9:0.1 to 10:90.